Be sure to Observe that beginning in 2005, Rolex began engraving the serial quantity around the inner bezel (often called the rehaut) beneath the crystal at the 6 o’clock place. Though the crystals on the 160xx technology of Datejust watches are still produced from acrylic, the sloped "pie pan" style https://www.watchesworld.com/a-history-of-watch-reference-numbers/